This disclosure relates generally to the field of fixed cutter drill bits. More specifically, the disclosure relates to drill bits having both shear cutters and “gouging” type cutters.
Fixed cutter bits known in the art include PDC bits, wherein a plurality of PDC cutters are affixed to a bit body in a selected arrangement on one or more blades formed in the bit body.
Gouging type cutters are used in drill bits for drilling mine shafts or tunnels, among other uses. Such bits are known in the art as “claw” bits, one example of which is sold under the trademark QUI-KLAW, which is a trademark of Drillhead, Inc. Such bits are known to be useful in drilling clay, unconsolidated sand, loose rock and gravel.
U.S. Pat. No. 8,505,634 issued to Lyons et al. describes a drill bit having gouging cutting elements disposed adjacent to shearing cutting elements on a blade on the bit body. The shearing cutting elements have a planar cutting face, while the gouging cutting elements have a non-planar cutting face, e.g., dome shaped or cone shaped.